浅谈爆破工程监理存在的问题及对策

目前我国对爆破工程实施安全监理仍处于探索阶段,还是相当粗放的状态。本文根据近年来的爆破工程安全监理实践和大量调研材料,分析了当前爆破工程监理存在的一些问题,并提出了解决问题的对策,以期与从事爆破工程安全监理的同行共同探讨。     

浅述爆破工程安全监理

介绍了国际上流行的"HSE"(H-健康;S-安全;E-环境)监理模式中的安全监理.安全监理是工程建设监理工作的一个重要研究课题.在阐述工程安全监理的基础上全面探讨了爆破工程安全监理的现状和意义,并就我国现行的爆破工程的内容进行了分析,进而提出了爆破工程安全监理的对策.     

综论爆破工程安全监理

从爆破工程特点的分析入手,介绍了拆除爆破、硐室爆破和中深孔爆破工程安全监理工作的基本方法和监理手段,对爆破安全监理组织的形式、原则和安全监理旁站点的选择、检查、记录等重要监理事项进行了论述。     

场平工程深孔爆破安全监理

安全在爆破工程中具有十分重要的地位,如何加强爆破实施过程中的安全监理工作,已引起社会各界的普遍重视。本文分析、总结了场平工程深孔爆破安全监理的实践经验,重点介绍了安全监理的主要内容,并对其中遇到的问题进行了探讨。为爆破工程安全监理制度的建立与完善积累了经验,同时也可供同类工程实施安全监理参考。     

场平工程深孔爆破安全监理

安全在爆破工程中具有十分重要的地位,如何加强爆破实施过程中的安全监理工作,已引起社会各界的普遍重视。本文分析、总结了场平工程深孔爆破安全监理的实践经验,重点介绍了安全监理的主要内容,并对其中遇到的问题进行了探讨。为爆破工程安全监理制度的建立与完善积累了经验,同时也可供同类工程实施安全监理参考。     

武汉饭店爆破拆除工程安全监理

在武汉饭店爆破拆除工程中实施了比较规范的爆破安全监理工作。文中介绍了该工程的概况 ,论述了爆破安全监理的主要工作内容。根据所获得的经验 ,指出了当前推行爆破工程安全监理工作中存在的问题和困难。     

武汉饭店爆破拆除工程安全监理

在武汉饭店爆破拆除工程中实施了比较规范的爆破安全监理工作。文中介绍了该工程的概况 ,论述了爆破安全监理的主要工作内容。根据所获得的经验 ,指出了当前推行爆破工程安全监理工作中存在的问题和困难。     

拆除爆破工程安全监理的实践探讨

从拆除爆破工程特点的分析入手,介绍了拆除爆破工程安全监理的基本方法和监理手段,对爆破安全监理组织和旁站点的选择、检查、记录进行了探讨.     

爆破工程现场监理视频监控系统的应用

确保爆破工程安全是爆破工程的永恒主题,当前爆破安全监理工作被广泛推广,一定程度上保证了爆破工程安全,但仍存在爆破监理工作现场记录的难题。基于此,利用现有视频监控技术及通用设备优化集成了一套基于互联网连接的便携式远程视频监控系统,并详细介绍了其在工程实例中的应用。该系统小巧灵活,安装、操作简便,可随时改变视频采集位置,解决了爆破现场环境复杂多变,安全监理工作难以全面到位的问题。视频资料可刻盘存档,供公安机关备案。可为爆破工程现场安全监理工作提供参考。     

高耸建筑物拆除爆破安全监理实践

以西湖第一高楼定向爆破拆除安全监理为例,重点介绍了监理工作的主要内容和基本方法,并对拆除爆破安全监理存在的一些突出问题进行了探讨。作者还就此工程实例谈了监理工作的效果与体会,可供拆除爆破工程监理参考。     

波传播法求解低频激励下水中加端板圆柱壳的振动

采用波传播法研究了低频下水中壳体的振动与响应。水中壳体由有限长加流体载荷的圆柱壳和两端的圆形端板组成,其中外部流体载荷用无限长模型进行近似处理。为了模拟推动系统的激励及船体上某一点激励,分别考虑了不同位置的轴向载荷和径向载荷,讨论了单个周向模态下的位移在总位移中的比重。主要研究了4种载荷,即作用在端板中心的轴对称载荷、作用在端板与圆柱连接处的轴向载荷、作用在连接处的径向载荷和作用在壳体中间的径向载荷,比较得出了轴对称和非轴对称、同一点不同方向载荷、同一方向不同位置载荷的响应位移的不同。此外,还研究了两端端板对不同载荷下水中壳体响应的影响,得出了端板主要抑制了壳体的较高阶模态下径向位移的结论。解析法结果与有限元法结果进行了比较,验证了该方法的正确性。     

On the Applications of Discontinuous Bessel Integrals to Chronoamperometry

Discontinuous Bessel integrals are applied to a boundary value problem related to chronoamperometry, with zero concentration at the disk satisfied on the average and the zero flux at the shroud satisfied approximately only. Current functions are derived, series expansion at long time and asymptotic expansion at short times are given. Plots of numerical calculations of current functions are presented.     

Criteria for the Evaluation of Photographic Lenses

Simplified test conditions for the evaluation of lenses based on MTF measurements are described, and criteria for interchangeable lenses for 35 mm cameras are proposed. Measurements are to be made for white light, at the infinite conjugate plane, on axis and at 0·7 field (15 mm off axis) positions, at full aperture and ?/5·6. The focus is to be adjusted at each aperture so as to give the best MTF response at 30 lines/mm on axis. The MTF responses at 15 and 30 lines/mm are to be examined for the evaluation of the lenses. Simple criteria based on the experimental data for about 100 different types of interchangeable lenses are proposed.     

Multiscale Toughening Mechanisms in Biological Materials and Bioinspired Designs

Biological materials found in Nature such as nacre and bone are well recognized as light‐weight, strong, and tough structural materials. The remarkable toughness and damage tolerance of such biological materials are conferred through hierarchical assembly of their multiscale (i.e., atomic‐ to macroscale) architectures and components. Herein, the toughening mechanisms of different organisms at multilength scales are identified and summarized: macromolecular deformation, chemical bond breakage, and biomineral crystal imperfections at the atomic scale; biopolymer fibril reconfiguration/deformation and biomineral nanoparticle/nanoplatelet/nanorod translation, and crack reorientation at the nanoscale; crack deflection and twisting by characteristic features such as tubules and lamellae at the microscale; and structure and morphology optimization at the macroscale. In addition, the actual loading conditions of the natural organisms are different, leading to energy dissipation occurring at different time scales. These toughening mechanisms are further illustrated by comparing the experimental results with computational modeling. Modeling methods at different length and time scales are reviewed. Examples of biomimetic designs that realize the multiscale toughening mechanisms in engineering materials are introduced. Indeed, there is still plenty of room mimicking the strong and tough biological designs at the multilength and time scale in Nature.     

The National High Magnetic Field Laboratory: Condensed Matter Science in Continuous Magnetic Fields

The National High Magnetic Field Laboratory (NHMFL) operates three facilities in support of magnet-related research. The main facilities are located at Florida State University, Tallahassee, Florida, the ultra-low-temperature high-magnetic-field facilities are located at the University of Florida, Gainesville, Florida, and the pulsed field facilities are located at the Los Alamos National Laboratory, Los Alamos, New Mexico. These facilities support a wide variety of magnet-related research capabilities that are open to all qualified users through a peer-reviewed proposal process. This paper summarizes the research capabilities at the DC facilities at the main facility of the NHMFL and the High B/T Facility at the University of Florida. A few select scientific achievements in the high field condensed matter sciences are presented to highlight the research capabilities available to all users. The NHMFL is supported by the United States National Science Foundation and the State of Florida.     

超细粉碎技术现状及发展趋势

综述了国内外超细粉碎技术及设备的现状、进展,指出了其发展趋势,从工作原理、结构特点等方面详细介绍了超细粉碎典型设备,同时又指出了近年来国内外在此领域中的新进展,基于现存问题指出了今后超细粉碎研究的方向。     

Reaction chemistry at joined interfaces between silicon nitride and aluminium

Joined interfaces of HIPed additive-free silicon nitride ceramics/aluminium braze bonded at a low temperature of 1073 K for 18 ks or at a high temperature of 1473 K for 1.8 ks in vacuum of 1.3 mPa and of β silicon nitride powders/aluminium powders bonded at the low temperature for 1.8 ks or 18 ks in the same vacuum are identified by analytical transmission electron microscopy and X-ray diffraction method. Mullite, some small crystals and β′-sialon are detected at the interface of the ceramics/aluminium braze bonded at the low temperature and 15R AIN-polytype sialon, β′-sialon, aluminium nitride, mullite and silica-alumina noncrystalline are detected at that bonded at the high temperature. At the interface of the two kinds of powders, aluminium nitride and silicon are also detected besides β′-sialon and silica-alumina noncrystalline even though the bonding was conducted at the low temperature. The interfacial reactions of the joints are influenced not only by bonding temperature but also by the oxide formed at the interface before bonded.     

Acoustic emission of composite materials in tensile tests at cryogenic temperatures

Tensile tests of fibre reinforced plastics are performed at cryogenic temperatures and simultaneously acoustic emission (AE) is observed to examine the microscopic deformation and fracture processes of these materials. AE behaviours at liquid helium temperature are different from those at liquid nitrogen temperature, although the mechanical behaviours are similar. From these results, correlations of the AE sources with the microscopic deformation and fracture processes are discussed.     

Luminescence from praseodymium doped AlN thin films deposited by RF magnetron sputtering and the effect of material structure and thermal annealing on the luminescence

Thin films of Praseodymium doped AlN are deposited on silicon (111) substrates at 77 K and 950 K by rf magnetron sputtering method. About 500–1000 nm thick films are grown at 100–200 watts RF power and 5–8 mTorr nitrogen, using a metal target of Al with Pr. X-rays diffraction results show that films deposited at 77 K are amorphous and those deposited at 950 K are crystalline. Cathodoluminescence studies are performed at room temperature and luminescence peaks are observed in a wide range from ultraviolet to infrared region. The most intense peak is obtained in green at 526 nm from amorphous films as a result from ³P₁→³H₅ transition. In crystalline films the intense peak was obtain in red at 648 nm as a result from ³P₀→³F₂ transition. Films are thermally activated at 1300 K for half an hour in a nitrogen atmosphere. Thermal activation enhances the intensity of luminescence. Two peaks at 488 nm and 505 nm merged after thermal activation, giving rise to a single peak at 495 nm.     

管状工件内表面真空镀膜方法的研究进展

本文针对管状工件内表面的真空镀膜方法进行了分类综述.介绍了国内外学者所开发研究的十余种镀膜方法,对各种方法的应用范围和特点进行了简要分析.最后总结提出尚存的问题.